1. Field of the Invention
This invention relates to a process for the manufacture on an industrial scale of pipe fitting components, more specifically, though not exclusively, of components forming part of an unit comprised of three components or pieces conjointly forming a so-called union for the connecting together of two tubes (see, for example, UNI 5211/70).
2. Description of the Prior Art
Pipe fitting components of the same type as, or similar to, those described above are well known and widely used, as well as the subject-matter of standard classification. They are generally obtained in the form of malleable iron castings that are then submitted to machining operations. However, this method of manufacture is becoming now more and more expensive and it has led, moreover, to products of comparatively reduced accuracy or to products that are required to be subjected to further considerable and thus expensive machining operations. In addition, the material involved, and as imposed by the conditions of formation of the castings, appear to be not ideally suited for the required uses, particularly in view of the stresses to which such pipe fitting components are, in general, likeky to be subjected.
As an alternative, it has been proposed to make the above pipe fitting components by cold or hot extrusion-coinage operations carried out by starting from a pellet of a suitable material such as, for example, brass and by the use of dies reproducing the final configuration of the desired components. Though, on the one hand, this method has permitted considerable accuracy to be achieved by utilisation of more suitable materials, on the other hand, it has given rise to further difficulties that have practically reduced its use on an industrial level to a significant extent. The above mentioned operations involve, in fact, application of very high forces of deformation and they require, therefore, the use of equipment which is particularly expensive and, this notwithstanding, which has a comparatively short life. Also the treated material must have specific properties and, therefore, it is relatively high in cost. Moreover, known extrusion-coining operations are slow operations due to the large powers that are involved, and thus the productive capacity is also reduced when conducting such operations.